The Granit oak (in Bulgarian : Гранитски дъб ) is a pedunculate oak ( Quercus robur ) tree that grows within the boundaries of Granit village, Bulgaria .
5-490: The oak measures 2.38 m (7 ft 10 in) in diameter and 7.46 m (24.5 ft) in girth at waist level and reaches 23.4 m (77 ft) in height, but only eastern side branches remain alive. In March 1982 samples were taken with a pressler drill , from which it was estimated that the tree was 1637 years old. With an estimated germination date of 345 AD, it is the oldest tree in Bulgaria and one of
10-407: Is a specialized tool used to extract a section of wood tissue from a living tree with relatively minor injury to the plant itself. The tool consists of a handle, an auger bit and a small, half circular metal tray ( the core extractor) that fits into the auger bit; the last is usually manufactured from carbide steel. It is most often used by foresters , researchers and scientists to determine
15-450: The age of a tree. This science is also called dendrochronology . The operation enables the user to count the rings in the core sample, to reveal the age of the tree being examined and its growth rate. After use the tool breaks down: auger bit and extractor fit within the handle, making it highly compact and easy to carry. Effective use of an increment borer requires specialized training. Samples are taken at breast height or stump height of
20-579: The oldest in Europe. In 1967 the Granit oak was declared a protected tree and included in the list of the natural monuments of Bulgaria. In 2010 the oak was featured prominently in a documentary Live Eternity (in Bulgarian : Жива Вечност ). 42°15′15″N 25°08′10″E / 42.254067°N 25.136080°E / 42.254067; 25.136080 Increment borer An increment borer
25-584: The tree trunk, depending on the user's objectives; during use the borer should be well lubricated, thus making it easier to use and preventing it from becoming stuck in the wood. As with any other tools, increment borers should be properly maintained to keep them in good working condition; should be thoroughly cleaned after each use and dried before storing. Sharpening kits are available and should be used regularly, before such bits become dull. Increment borers come in different lengths and diameters and have different types of threads . The most common diameters are
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